The lines of longitude are parallel, but the globe is not a perfect sphere. The Earth is not a perfect sphere because it’s oblate spheroidal or flattened at the poles and bulging around the equator.
What does this mean?
The earth isn’t round; it’s slightly egg-shaped. That’s why longitude lines are not parallel, because they don’t cross at right angles in the same way on a globe as they do on a flat map.
The reason for this is that the earth is not a perfect sphere, but rather an oblate spheroid (or “oblate spheroidal”, as some might say). This means that it takes on an oblong shape when viewed from above (like a basketball).
This means that longitude lines don’t cross at right angles in the same way on a globe as they do on a flat map.
The equator is one of two great circles (the other being its opposite) that divide the Earth into Northern and Southern Hemispheres. It’s an imaginary line around our planet that passes through both poles and all places have zero degrees latitude (North or South). It does not pass through any place at 0° longitude though!
Last modified: August 2, 2022